Intellectual realism in children's drawings of cubes

Ninety-six children copied simple line drawings of perspective views of cubes and similar designs unlikely to be seen as representing objects. The views of cubes were copied much less accurately than the non-object patterns, and the errors made in copying the cubes involved replacement of properties specific to the single perspective view by properties more appropriate to the object itself. Some copies were drawn with the child continually looking at the model and unable to see his own copy, others were drawn in the normal way. Copies made in the former way were more accurate, but even under these conditions cubes were copied less accurately than the non-object patterns. The disadvantage of object pictures, as far as literal copying accuracy is concerned, was still present at 9 1/2 years of age, but was less than at 7 1/2. Two possible explanations are discussed. One is in terms of computational complexity, the other in terms of graphic motor schema. On the basis of the drawings obtained a few suggestions are made about the content and development of the data-structures for cubes.     

Auditory lateralization: An effect of rhythm

Recall of monaurally presented semantically anomalous sentences, which had either neutral or rhythmic timing, was tested at the right ear, at the left ear, and on transfer from one ear to the other. The component words, being computer stored digitized waveforms, had identical acoustic structure in the two conditions. In the rhythmic condition there was not only an overall advantage in the second half of the experiment but also an asymmetric transfer effect such that this advantage did not appear when the left ear was tested after the right. It is proposed that functional lateralization be viewed as an adaptive, dynamic, organizational factor.     

Multiple causal pathways in attention-deficit/hyperactivity disorder – Do emerging executive and motivational deviations precede symptom development?

The multiple causal pathways model on the etiology of attention-deficit/hyperactivity disorder (ADHD) is well established. However, developmental implications of the model are not yet sufficiently analyzed. The model implies that critical neural and neuropsychological deviations from normative development precede secondarily developing ADHD symptoms. Cognitive, “cool” inhibitory control (CIC) and reward-related, “hot” functions (RRF) are regarded as neuropsychological basic deficits that indicate independent causal pathways. Both functions involve top-down control networks that undergo major normative developmental changes in the preschool period. We formalized the following assumptions in a path model: (a) CIC and RRF predict change in ADHD symptoms in the preschool period, (b) the reverse is not true, and (c) CIC and RRF independently contribute to this prediction. A community-based sample of 125 (71 boys) preschoolers was assessed at at age 4 and 5 years. At each assessment wave, CIC and RRF were measured by a battery of age-appropriate valid tasks. ADHD symptoms were measured by a clinical parent interview. Evaluation of model fit using manifest maximum likelihood parameter estimation clearly supported the hypothesized path model while controlling for gender of child and maternal education level. Thus, regarding the basic deficits of CIC and RRF, the results add evidence on the developmental implications of the multiple causal pathways model. Our findings point to the potential significance of these early emerging characteristics as indicators of risk and as targets for preventive interventions.     

Executive function and weight status in children: A one-year longitudinal perspective

There is considerable evidence for an association between obesity and impaired executive function (EF) in adolescents and adults. However, little research has examined EF in overweight or obese children. Furthermore, data on EF in underweight individuals is lacking. In addition, there is no consensus on the directionality of the relationship between Body Mass Index (BMI) and EF, and longitudinal studies are rare. Thus, the present study examined whether children differ in their performance on a battery of EF tasks depending on their weight status (underweight, normal-weight, overweight), and investigated the longitudinal cross-lagged associations between EF and BMI. Hot EF (delay of gratification, affective decision-making), cool EF (attention shifting, inhibition, working memory [WM] updating), and BMI were assessed in 1,657 German elementary-school children at two time points, approximately one year apart. Overweight children exhibited slightly poorer attention shifting, WM updating, and affective decision-making abilities as compared to normal-weight children. Unexpectedly, they did not show any deficits in inhibition or delay of gratification. EF levels of underweight children did not differ significantly from those of normal-weight children. Furthermore, poor attention shifting and enhanced affective decision-making predicted a slightly higher BMI one year later, and a higher BMI also predicted poorer attention shifting and WM updating one year later. The latter association between BMI and subsequent EF scores, however, diminished when controlling for socioeconomic status. Results indicate that hot and cool EF plays a role in the weight development of children, and might be a promising factor to address in preventive interventions.     

Hot and Cool Forms of Inhibitory Control and Externalizing Behavior in Children of Mothers who Smoked during Pregnancy: An Exploratory Study

This study examined whether children exposed to prenatal smoking show deficits in “hot” and/or “cool” executive functioning (EF). Hot EF is involved in regulation of affect and motivation, whereas cool EF is involved in handling abstract, decontextualized problems. Forty 7 to 9-year-old children (15 exposed to prenatal smoking, 25 non-exposed) performed two computerized tasks. The Sustained Attention Dots (SA-Dots) Task (as a measure of “cool” inhibitory control) requires 400 non-dominant hand and 200 dominant hand responses. Inhibitory control of the prepotent response is required for dominant hand responses. The Delay Frustration Task (DeFT) (as a measure of “hot” inhibitory control) consists of 55 simple maths exercises. On a number of trials delays are introduced before the next question appears on the screen. The extent of response-button pressing during delays indicates frustration-induced inhibitory control. Prenatally exposed children showed poorer inhibitory control in the DeFT than non-exposed children. A dose–response relationship was also observed. In addition, prenatally exposed children had significantly higher (dose-dependent) conduct problem- and hyperactivity-inattention scores. There were no significant group differences in inhibitory control scores from the SA-Dots. These results indicate that children exposed to prenatal smoking are at higher risk of hot but not cool executive function deficits.     

Errors in children's subtraction

Many of the errors that occur in children' subtraction are due to the use of incorrect strategies rather than to the incorrect recall of number facts. A production system is presented for performing written subtraction which is consistent with an earlier analysis of the nature of such a cognitive skill. Most of the incorrect strategies used by schoolchildren can be accounted for in a principled way by simple changes in the production system, such as the omission of individual rules or the inclusion of rules appropriate to other arithmetical tasks. The production system model is evaluated against a corpus of over 1500 subtraction problems done by 10-year olds and is shown to account for about two-thirds of the (nonnumber fact) errors. It also provides an alternative, simpler interpretation of the subtraction errors analysed by Brown and Burton (1978). Some implications for teaching are discussed.     

Syllogistic inference

This paper reviews current psychological theories of syllogistic inference and establishes that despite their various merits they all contain deficiencies as theories of performance. It presents the results of two experiments, one using syllogisms and the other using three-term series problems, designed to elucidate how the arrangement of terms within the premises (the ‘figure’ of the premises) affects performance. These data are used in the construction of a theory based on the hypothesis that reasoners construct mental models of the premises, formulate informative conclusions about the relations in the model, and search for alternative models that are counterexamples to these conclusions. This theory, which has been implemented in several computer programs, predicts that two principal factors should affect performance: the figure of the premises, and the number of models that they call for. These predictions were confirmed by a third experiment.     

The height of handwriting

An experiment is described that examines the basis of the control of vertical amplitude (height) of handwriting. It is shown that changes in movement duration accompany changes in height whether the latter are associated with instructions to write larger than normal (between words) or because the letters to be written (e, l) differ in height (within words). The proportional differences in movement duration match the proportional differences in amplitude between words but not within words. It is concluded that two different time-based mechanisms are invoked for handwriting height control: interval adjustment for writing size changes between words and duration selection for letters differing in height within a word.